According to the Infusion Nurses Society, there are two purposes for flushing a vascular access device 1) to maintain catheter patency and 2) to prevent contact between incompatible fluids and medication. All vascular access devices should yield a positive blood return when aspirated and are considered non-functioning when blood cannot be obtained. Flushing of a catheter is defined as a manual injection of a saline solution to clear the catheter. Locking of a catheter is defined as the injection of a limited volume of a liquid following the catheter flush, for the period when the catheter is not used, to prevent intraluminal clot formation and/or catheter colonization.
Vascular access devices are flushed after each infusion to clear the infused medication from the catheter lumen, therefore by reducing the risk of contact between incompatible medications. Each vascular access device lumen is locked after completion of the final flush to decrease the risk of intraluminal occlusion, depending on the solution used, to reduce catheter related bloodstream infections. According to the Infection Control Resource study, 87% of bloodstream infections are catheter-related, and it is the most life threatening of all healthcare acquired infections and accounts for significant medical costs.
The INSOP Recommend the Use of Single-Dose Systems (eg. single-dose vials or prefilled label syringes) for all vascular access devices flushing and locking:
- A syringe or needle/cannula should be considered contaminated once it has been used to enter or connect to a patient’s IV solution container or administration set.
- Use commercially available prefilled syringe preparation and aid optimal flushing technique and objectives.
- If multi-dose vials must be used, dedicate a vial to a single patient. Do not store multi-dose vials in patient treatment areas and store according to manufacturer direction for use; discard if sterility is compromised or questionable.
- Do not use IV solution containers (eg, bags or bottles) as a source for obtaining flush solutions.
- Inform patients that prefilled flush syringes are associated with disturbances in taste and odor, which has been found to be more prominent with flushing CVADs than with PIVCs. The cause is thought to be substances leaching from the plastic syringe due to sterilization methods. These sensations may be significant enough to impact appetite and may increase nausea, especially if administered rapidly.
Standardized protocols for flushing and locking solutions are established within each organization.
Health Line International Corp. is not responsible for any errors, omissions, injury, loss, or damage arising from or relating to the use (or misuse) of any information, statements, or conclusions contained in or implied by the contents of this document or any of the source materials. This content is not intended to replace professional medical advice.
Gorski LA, Hadaway L, Hagle ME, et al. Infusion therapy standards of practice. J Infus Nurs. 2021;44(suppl 1):S1S2-S224. Doi:10.1097/NAN.0000000000000396
Goossens, G. (2015, May 14). Flushing and locking of Venous Catheters: Available evidence and Evidence Deficit. Retrieved February 26, 2021, from https://www.hindawi.com/journals/nrp/2015/985686/
Hadaway, Lynn. (2006). Flushing vascular access catheters: Risks for infection. Infection Control Resource.